This invention relates to solid state circuits and relates more particularly to solid state crosspoint circuit arrangements for use in telephone exchanges and to telephone exchanges incorporating such solid state crosspoint circuit arrangements.
Up to the present time the use of solid state techniques within the switchblock (the interconnection field) of a telephone exchange have been limited, in the main, to arrangements that are akin to reed relay approaches, the most popular being based on a P.N.P.N. diode (silicon controlled rectifier -- SCR) crosspoint. The SCR crosspoint however, suffers from the disadvantages that, because of its ON resitance it is marginal as regards exchange insertion loss and also it suffers from cross-talk problems.